Next door in Austria I've seen employment contracts (from local Mittlestand family owned companies in the automotive sector) where it was specified that "in case of sick leave, the employee agrees to health checks by the company's own GP at the company's expense, even if you already have been written off sick by your own GP." I've never been more disgusted.

Then again, I've also read in the news here of employers hiring private investigators to catch employees fraudulently claiming sick leave, then firing them and suing them claiming back wages paid along with the P.I. fees.

To play the devil's advocate, since sick leaves are costly for businesses here, it probably sucks hard if you have a few employees abusing it heavily to avoid work (even though it's common knowledge that everyone here takes a sick day off work every now and then after a heavy night out partying and drinking or stuff like that).